Which one of these statements is true regarding hot pluggable PCIe and PCI-X slots in a Power 550?（）

• A、Cards can be added and then enabled via Hardware Management Console (HMC) GUI or command line. 
• B、The HMC allows access to the Advanced System Management Interface (ASMI), where the slots can be managed. 
• C、If the empty slot was already allocated to an LPAR, the LPAR can use the card after the cfgmgr script has been run. 
• D、The Hardware Management Console (HMC) GUI can guide a customer through the process of adding a card to an empty slot.